Montek LC Dosing Recommendations
Montek LC (montelukast + levocetirizine combination) should be dosed according to age: for children 6-14 years, give montelukast 5 mg with levocetirizine 5 mg once daily in the evening; for children 2-5 years, give montelukast 4 mg with levocetirizine 1.25 mg twice daily; and for adults and adolescents ≥15 years, give montelukast 10 mg with levocetirizine 5 mg once daily. 1
Age-Specific Dosing
Adults and Adolescents ≥15 Years
- Montelukast 10 mg once daily (film-coated tablet) 2
- Levocetirizine 5 mg once daily 1
- Administer in the evening based on pharmacodynamic profile 1
- The 10-mg dose was selected as optimal based on dose-ranging studies showing maximal improvement in airway function without additional benefit at higher doses 2
Children 6-14 Years
- Montelukast 5 mg chewable tablet once daily in the evening 3, 1
- Levocetirizine 5 mg once daily 1
- The 5-mg dose provides systemic exposure comparable to the adult 10-mg dose, making separate dose-ranging studies unnecessary 4, 5
- Mean systemic exposure of the 5-mg chewable tablet in this age group is similar to the 10-mg film-coated tablet in adults 2
Children 2-5 Years
- Montelukast 4 mg chewable tablet once daily in the evening 1, 6
- Levocetirizine 1.25 mg twice daily 1
- The 4-mg dose is FDA-approved based on safety data and demonstrated efficacy in multiple asthma control parameters 1, 6
- Clinical benefit is evident within 1 day of starting therapy 6
Children 1-2 Years (for perennial allergic rhinitis)
- Montelukast 4 mg once daily 1
- Levocetirizine 0.125 mg/kg twice daily 1
- The 4-mg oral granule formulation should be used for patients 12-23 months of age 2
Important Clinical Considerations
Administration Timing
- Evening dosing is recommended for montelukast based on its pharmacodynamic profile, though pharmacokinetics are similar whether dosed morning or evening 1, 2
- May be administered without regard to food, though taking with meals may improve gastrointestinal tolerability 7
Special Populations
Renal Impairment:
- Levocetirizine requires dose adjustment in moderate renal impairment 1
- No montelukast dose adjustment needed, as the drug and metabolites are excreted almost exclusively via bile 2
Hepatic Impairment:
- No dose adjustment required for mild-to-moderate hepatic insufficiency 2
- Patients with cirrhosis show 41% higher montelukast AUC but elimination half-life only slightly prolonged (7.4 hours vs. normal) 2
Elderly:
- No dose adjustment required; pharmacokinetic profile similar to younger adults with only slightly longer plasma half-life 2
Common Pitfalls to Avoid
- Do not use higher doses expecting better efficacy: Clinical trials demonstrated no additional benefit with montelukast doses above 10 mg once daily in adults, even with doses up to 200 mg 2
- Be aware of neuropsychiatric adverse effects: Recent FDA warnings emphasize caution and reserve montelukast for selected patients 8
- Avoid in pregnancy for combination products: While montelukast safety data exist, combination therapy requires careful consideration
- Monitor for drug interactions: Phenobarbital and rifampin decrease montelukast AUC by approximately 40%; appropriate clinical monitoring is reasonable when co-administered 2
Pharmacokinetic Rationale
The pediatric dosing strategy is based on achieving comparable systemic exposure (AUC) to the adult 10-mg dose rather than conducting separate dose-ranging studies in children 4, 5. This approach is justified because asthma is treated similarly across age groups with the same medications 4. The plasma half-life of montelukast ranges from 2.7 to 5.5 hours in healthy young adults, with minimal drug accumulation (14%) during once-daily dosing 2.